Analysis of plasma biomarker and tumor genetic alterations from a phase II trial of lenvatinib in patients with advanced endometrial cancer

5591

Background: Lenvatinib is an oral receptor tyrosine kinase inhibitor targeting VEGFR1-3, FGFR1-4, RET, KIT, and PDGFRβ. A phase 2 study in patients with advanced endometrial cancer following 1 or 2 prior platinum-based treatments was performed and is presented in a separate abstract. Here we report potential predictive markers of clinical benefit. Methods: Pre- and post-treatment plasma samples collected from 122 of 133 treated subjects were analyzed for 50 circulating cytokine and angiogenic factors (CAFs) using ELISA and multiplex assay platforms; 107 archival tumor tissues obtained from 133 enrolled subjects were analyzed for gene mutation (mut) (81 samples) and gene expression profiling (GEP) (64 samples). For GEP analysis, the NanoString nCounter platform was used to measure the expression level of approximately 300 genes identified preclinically as relevant. Correlation with clinical outcome measures including maximal tumor shrinkage (MTS), objective response rate (ORR), PFS, and OS was performed. Results: Clinical correlation identified baseline levels of 7 CAFs related to angiogenesis (Ang-2, IL-8, HGF, VEGFA, PlGF, Tie-2, and TNFa) that associated with survival. Only baseline levels of Ang-2 associated with greater MTS (R=0.36 [Spearman], P<0.001), ORR (61% vs 18%), mPFS (9.5 vs 3.7 mos), and mOS (23 vs 8.9 mos) as determined using a defined cut-off value for baseline Ang-2. In gene mut analysis, no significant correlations were observed among the genes tested. Mut in PIK3CA showed a trend toward shorter OS (p = 0.085). In GEP analysis, expression levels of approximately 90 genes correlated with clinical outcome. Combination of GEP and CAF signatures identified signaling pathways, including Ang-2, that associated with OS. Clinical and preclinical GEP analysis identified overlapping gene signatures involving MAPK and PI3K signaling pathways that contributed to lenvatinib resistance. Conclusions: Baseline circulating Ang-2 levels may potentially predict outcomes in patients with advanced endometrial cancer and require further examination. This may provide a basis for stratification of patients in future clinical trials. Clinical trial information: NCT01111461.

A phase II trial of lenvatinib in patients with advanced or recurrent endometrial cancer: Angiopoietin-2 as a predictive marker for clinical outcomes

5520

Background: Lenvatinib is an oral receptor tyrosine kinase inhibitor targeting VEGFR1-3, FGFR1-4, RET, KIT, and PDGFRβ. The importance of angiogenesis in endometrial cancer (EC) highlights the need to understand clinical mechanisms of escape (eg, angiopoietin-2 [Ang-2]) from antiangiogenic therapy. Methods: Patients (pts) had metastatic/unresectable EC after 1 or 2 prior platinum-based treatments (Tx), ≤2 prior chemotherapies, and ECOG PS ≤2. Pts received lenvatinib 24 mg once daily until disease progression or development of unmanageable toxicities. Primary endpoint was objective response rate (ORR: complete + partial response [CR+PR]) by RECIST 1.1. Archival tumor tissue and baseline (BL) and post-Tx plasma samples were collected for molecular analyses (reported elsewhere). Results: 133 pts were treated (median age: 62 y) and evaluated for safety, efficacy, and molecular correlative analysis. Dose reduction (31%) or Tx discontinuation (31%) occurred for toxicity. Median Tx duration was 112 days. The most common adverse events were hypertension 55% (Gr 3/4: 33%), fatigue 42% (Gr 3: 12.8%), diarrhea 35% (Gr 3: 5.3%), decreased appetite 35% (Gr 3: 2.3%), and nausea 32% (Gr 3: 3%); 1 pt had Gr 5 asthenia. Bowel obstruction, fistula formation, and perforation occurred in 3.8%, 2.3%, and 1.5%, respectively. Confirmed CR+PRs were observed in 19 pts (14.3%) by independent review (IRR) and 29 pts (21.8%) by investigator assessment (Inv). mPFS was 5.4 mos and mOS was 10.6 mos. Among 50 serum factors tested, only BL plasma Ang-2 correlated with maximal tumor shrinkage, R = 0.36 (Spearman), p < 0.001; ORR; PFS; and OS. The 24 pts with low BL Ang-2 plasma levels (cut-off value <2082 pg/mL) were compared with the 98 pts with high BL Ang-2 (>2082 pg/mL) and improved ORR (61% vs 18%), mPFS (9.5 vs 3.7 mos), and mOS (23 vs 8.9 mos) were observed. Conclusions: Lenvatinib in this population was tolerable and resulted in a 14.3% (IRR) and 21.8% (Inv) ORR and mOS of 10.6 mos.Low BL Ang-2 level appears to predict clinical benefit in a subset of pts with advanced EC who may achieve high response rates and prolonged overall survival. Further assessment is warranted. Clinical trial information: NCT01111461.

A phase II study of the multitargeted kinase inhibitor lenvatinib in patients with advanced BRAF wild-type melanoma

9026

Background: Lenvatinib is an oral receptor tyrosine kinase inhibitor targeting VEGFR1-3, FGFR1-4, RET, KIT, and PDGFRβ. Melanoma responses in the phase I study led to this multicenter phase II trial of lenvatinib in separate cohorts of BRAF mutant and BRAF wild-type (wt) melanoma to provide an estimate of efficacy and to identify molecular correlates of clinical benefit. Primary analyses of clinical outcomes for the BRAF wt cohort are reported here; the BRAF mutant cohort will be presented at a later date. Methods: Eligible patients (pts) had stage IV or unresectable stage III BRAF wt melanoma with ≥1 prior treatment (26/96 [27%] pts received ≥3 treatments) and no prior VEGF-targeted therapy. Lenvatinib 24 mg once daily with dose reduction for toxicity was administered until disease progression or unmanageable toxicities. Primary endpoint was response rate by independent review (IRR) using RECIST 1.1. Archival tumor tissue and baseline and posttreatment serum samples were collected for molecular analysis. Results: 93 pts were treated (median [m] age: 64 y; male: 69%; 95% AJCC stage IV). Confirmed partial responses (PRs) were observed in 8 pts (9%) with a clinical benefit rate (CR+PR+durable SD ≥23 wks) of 32% by IRR. mPFS was 3.7 mos (95% CI, 2.5-4.0) by IRR and mOS was 9.5 mos (95% CI, 8.3-12.9); 46% pts required dose reduction for management of toxicity; 12% were withdrawn from therapy due to toxicity. Treatment-related adverse events reported in ≥20% pts included hypertension 59% (34% Gr 3/4), fatigue 58% (16% Gr 3/4), nausea 44% (3% Gr 3/4), diarrhea 43% (2% Gr 3/4), decreased appetite 38%, vomiting 29% (2% Gr 3), dysphonia 27%, and proteinuria and headache 26% each (4% and 1% Gr 3/4). Serum biomarker analysis showed baseline levels of serum angiogenic factors, such as angiopoietin-2, correlated with OS. More extensive biomarker analyses are reported in an accompanying abstract. Conclusions: Lenvatinib administered to pts with advanced BRAF wt melanoma was associated with frequent but manageable toxicity. Clinical benefit was seen in some pts. Predictive biomarkers for response to lenvatinib, such as the serum level of angiogenic factors, may be useful for future clinical trials. Clinical trial information: NCT01136967.

Eribulin monotherapy versus treatment of physician's choice in patients with metastatic breast cancer (EMBRACE): a phase 3 open-label randomised study

BACKGROUND

Treatments with survival benefit are greatly needed for women with heavily pretreated metastatic breast cancer. Eribulin mesilate is a non-taxane microtubule dynamics inhibitor with a novel mode of action. We aimed to compare overall survival of heavily pretreated patients receiving eribulin versus currently available treatments.

METHODS

In this phase 3 open-label study, women with locally recurrent or metastatic breast cancer were randomly allocated (2:1) to eribulin mesilate (1·4 mg/m(2) administered intravenously during 2-5 min on days 1 and 8 of a 21-day cycle) or treatment of physician's choice (TPC). Patients had received between two and five previous chemotherapy regimens (two or more for advanced disease), including an anthracycline and a taxane, unless contraindicated. Randomisation was stratified by geographical region, previous capecitabine treatment, and human epidermal growth factor receptor 2 status. Patients and investigators were not masked to treatment allocation. The primary endpoint was overall survival in the intention-to-treat population. This study is registered at ClinicalTrials.gov, number NCT00388726.

FINDINGS

762 women were randomly allocated to treatment groups (508 eribulin, 254 TPC). Overall survival was significantly improved in women assigned to eribulin (median 13·1 months, 95% CI 11·8-14·3) compared with TPC (10·6 months, 9·3-12·5; hazard ratio 0·81, 95% CI 0·66-0·99; p=0·041). The most common adverse events in both groups were asthenia or fatigue (270 [54%] of 503 patients on eribulin and 98 [40%] of 247 patients on TPC at all grades) and neutropenia (260 [52%] patients receiving eribulin and 73 [30%] of those on TPC at all grades). Peripheral neuropathy was the most common adverse event leading to discontinuation from eribulin, occurring in 24 (5%) of 503 patients.

INTERPRETATION

Eribulin showed a significant and clinically meaningful improvement in overall survival compared with TPC in women with heavily pretreated metastatic breast cancer. This finding challenges the notion that improved overall survival is an unrealistic expectation during evaluation of new anticancer therapies in the refractory setting.

FUNDING

Eisai.

From genes to geography: a genetic similarity rule for arthropod community structure at multiple geographic scales

We tested the hypothesis that leaf modifying arthropod communities are correlated with cottonwood host plant genetic variation from local to regional scales. Although recent studies found that host plant genetic composition can structure local dependent herbivore communities, the abiotic environment is a stronger factor than the genetic effect at increasingly larger spatial scales. In contrast to these studies we found that dependent arthropod community structure is correlated with both the cross type composition of cottonwoods and individual genotypes within local rivers up to the regional scale of 720,000 km(2) (Four Corner States region in the southwestern USA). Across this geographical extent comprising two naturally hybridizing cottonwood systems, the arthropod community follows a simple genetic similarity rule: genetically similar trees support more similar arthropod communities than trees that are genetically dissimilar. This relationship can be quantified with or without genetic data in Populus.

E7389, a novel anti-tubulin, in patients with refractory breast cancer

653

Background: E7389 is a synthetic analog of halichondrin B, with a broad anti- proliferative activity against tumor cells. Methods: E7389 was evaluated in an open-label, single-arm Phase II trial as monotherapy for patients with refractory breast cancer (≥2 prior chemotherapy regimens, which must have included an anthracycline and a taxane). E7389 was administered as an IV bolus of 1.4 mg/m2 on Days 1, 8, and 15 of a 28-day cycle (group 1), or on Days 1 and 8 of a 21-day cycle (group 2). The primary efficacy endpoint was ORR. Results: As of 9 December 2005, 88 patients had received treatment, 68 in group 1 and 20 in group 2. Median age was 55 yrs (range 36–84) and ECOG performance status 0–1. Sixty-six percent of the tumors were ductal carcinomas, 6% lobular, and 27% were unclassified. Sixty percent of the tumors were ER+, 47% PR+, and 17% Her2/neu 3+. The patients had received at least two previous regimens, with a median number of 5 (range 2–14). Forty-eight percent of the patients had also used hormonal therapy. Forty-nine patients in group 1 and 12 patients in group 2 had completed their 2nd cycle of treatment, and twenty-one in group1 and 1 in group 2 their 4th cycle. Safety: The major toxicity related to study drug was neutropenia. Among 73 patients with preliminary safety data available, two patients had Grade 3 febrile neutropenia, and 31 had Grade 3 or 4 neutropenia or leukopenia. The other Grade 3 toxicities encountered in more than two patients were dehydration (4 patients) and dyspnea (4 patients). Grade 3 peripheral neuropathy was reported in 2 patients. Efficacy: At the end of cycle four there were 10 (15.2%) confirmed partial responses (PRs) out of 66 evaluable patients in group 1, and 1 confirmed PR (5.6%) out of 18 evaluable patients in group 2. The median duration of confirmed responses was 113 days. Conclusions: Based on the safety and efficacy in this refractory breast cancer population, E7389 appears to be a therapy worthy of continued investigation in patients with heavily pretreated breast cancer. In order to comply with the current demand for individualized cancer care, bio-markers which would predict the sensitivity to E7389 are being searched in the tumor samples of the patients in the current and forthcoming studies.

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